The present disclosure relates generally to light redirection, and specifically relates to a Fresnel assembly for light redirection in eye tracking systems.
Eye tracking refers to the process of detecting the direction of a user's gaze, which may comprise detecting an orientation of an eye in 3-dimentional (3D) space. Eye tracking in the context of headsets used in, e.g., virtual reality and/or augmented reality applications can be an important feature. Conventional systems commonly use, e.g., a number of infrared light sources to illuminate the eye light, and a camera is used to image a reflection of the light sources from the eye. Traditionally, eye tracking systems use beam splitters to redirect infrared light reflected from the eye to the camera. However, beam splitters are often large, cumbersome, and unsuitable for HMDs used in augmented reality (AR), mixed reality (MR), and virtual reality (VR) systems.